These are either biennials or weak perennials. Cutting back before they go to seed is one way of prolonging their life. I've had The Watchman (nigra) going for a number of years now by cutting back as soon as it finishes flowering.
I am also growing a more perennial kind (rugosa) which lives on from year to year with no problems but has a limited color range. - mostly yellow.

Thanks you so much! This helps me a lot . Now I will watch and when they are finished blooming cut them down. How far down do you cut?

Also I believe cutting them down and getting rid of the leaves can prevent/deter the evil rust.

How far down should they be cut? THanks

I cut mine down to the ground. I also shake them to loosen any seeds that I haven't already harvested. I'm not sure if the same plants come back each year or if new ones grow from fallen seeds, but I always have plenty of plants sprout up every spring. They are supposedly biennials but mine always bloom every year, new plant or old.

My mother had what she called a Zebra Mallow Hollyhock. I would like some information on this plant and where I might find it. It is reddish purple with white stripes. I have tried nurserys, seed catalogs,etc.etc.

ronny - what you're looking for is Malva Sylvestris and "Zebrina" is the cultivar. Quite popular so should be available in catalogs or online.

Well here my regular ol' HH's are very STRONG perennials. I've had the same plants/clumps bloom year after year from the same root stalk; most winters they don't even die all they way down. I know because I haven't let mine re-seed! I go out daily when they are blooming and clip off any seed pods found...of course I always miss a few but they still come back bigger and better every year.

Try Bayer 3 in 1 systematic rose care for the rust. It says every month but I use it on my hollyhocks every 6 -8 weeks and they do fine.

To get rid of rust on Hollyhocks, someone on another forum recommended amending the soil with cornmeal. I tried it and it worked.